Investigators are still trying to determine who killed two Black lesbians in Houston last week, but police on Thursday made a surprising arrest in the case.

Britney Cosby and her girlfriend, Crystal Jackson, both 24, were murdered in Houston, according to police, and their bodies were dumped near a trash bin outside a convenience store in Galveston, Texas.

Initial reports raised fears of a random hate crime, but police arrested Cosby's father, James Larry Cosby, on Thursday. And this is where the gruesome tragedy becomes even more troubling.

James Cosby, 46, apparently had difficulty accepting his daughter's romantic relationship with a woman. The elder Cosby allegedly told his daughter, "Don't throw that gay (expletive) around in this house," according to a report in the Houston Chronicle.

That's an odd statement of condemnation, considering James Cosby had just returned to the house in October after serving a two-year prison sentence for failing to comply as a sex offender. Cosby had previously been convicted of the sexual assault of a 22-year-old woman.

I found Mr. Cosby's hypocrisy shocking, but Sharon Lettman-Hicks, the executive director and CEO of the National Black Justice Coalition (NBJC), told me she was not surprised by it. "The hypocrisy of masculinity and feeling that women are property and should be dominated in a certain way is quite historical, especially for sex offenders," she said.

Lettman-Hicks just returned last month from Houston, where she attended the annual "Creating Change" conference for LGBT leaders, but she described Mr. Cosby's views on homosexuality as "yet another case" where some see homosexuality as worse than any other issue in the community.

"We're still the slave of the slaves," added Maurice Franklin, a founding board member of NBJC, who lives in Texas. "You could be a convicted child rapist and the community would accept you with open arms," said Franklin. "But if you're gay or lesbian, they want to throw you out."

That's a strong indictment, but both Franklin and Lettman-Hicks quickly warn outsiders not to paint with too broad a brush in drawing conclusions. "I want to be careful not to cast [Larry Cosby] as all Black men or in any way shape or form take this beyond his character," Lettman said. She noted that Cosby's other family members interviewed in the media seemed supportive of their relationship.

Similarly, Franklin brought up the names of Michael Sam, Brittney Griner and Jason Collins as a contrast to the Houston killing to show that some well-known Black LGBT people are supported by their communities. "It's a paradox," said Franklin. "On one side there's an affirming community to come out to and support them, and in the same community there's so much hatred against Black gays and lesbians," he said.

Rev. Ivan Jackson, the father of Crystal Jackson, who was killed in the Texas murders, expressed the paradox from a personal perspective. "I did not agree with her sexual orientation either," he told Fox 28 Houston. "But I would not kill my daughter and Britney and then take them to Galveston and hide it. I love all my children the same," he said.

Actually, this is not just an issue about Christianity. Cosby, the father who police suspect may have killed his daughter, was reportedly a practicing Muslim who wrote notes about homosexuality in his Koran. But there seems to be a broader issue here about the effects of using religious beliefs to justify anti-gay hatred.

Perhaps the preachers, priests, imams, rabbis and ministers who condemn homosexuality from their pulpits may not see the connection, but the parishioners in their congregations often take those damning messages to heart. Thus, even a convicted sex offender with a long rap sheet could possibly justify murdering his own daughter for what he may have perceived as the far worse crime of homosexuality.

Stephanie Russell, who lives in Houston, may offer some insight, both as a Texan and as a Black lesbian. Russell says she has "an understanding" with her mom and dad. "My parents don't agree with my sexuality either, but it ends in the disagreement," she said.

Russell, who is active in the local Black LGBT community, told me in an interview that she's noticed some Black men "have a problem" whenever they see two women together who are lesbians. "If they feel like they can't participate, then it's an issue," she said. Russell describes these men as "aggressive" and said they make her feel "really uncomfortable." But this is Texas, and Russell has a concealed handgun license and keeps a .22 caliber gun in her car for protection.

It shouldn't take all that to be safe.

Despite all the progress in recent years, ordinary Black LGBT Americans often face their biggest challenges at home. Yes, we have an African-American president who supports marriage equality. Yes, 17 states and the District of Columbia allow same-sex marriage. Yes, openly gay athletes have emerged in the NBA, WNBA and soon the NFL. Yes, we even have rappers presiding over marriage ceremonies at the Grammys. And yes, there was an openly gay host of the Oscars again this year.

But none of that means a thing if you're not accepted by your own family.

Keith Boykin is a New York Times best-selling author and former White House aide to President Clinton. He attended Harvard Law School with President Barack Obama and currently serves as a TV political commentator. He writes commentary for BET.com each week.

The opinions expressed here do not necessarily reflect those of BET Networks.

BET National News - Keep up to date with breaking news stories from around the nation, including headlines from the hip hop and entertainment world. Click here to subscribe to our newsletter.